This happened to me too in Chrome on Mountain Lion. Version 20.0.1132.57

Looks like a browser bug. I've opened built in dev tools, selected card background image (image that was appended by script at the end of body), in style disabled z-index, image appeared on top of card. Then I've enabled z-index and image showed up correctly behind card.

This happened to me too in Chrome on Mountain Lion. Version 20.0.1132.57

Looks like a browser bug. I've opened built in dev tools, selected card background image (image that was appended by script at the end of body), in style disabled z-index, image appeared on top of card. Then I've enabled z-index and image showed up correctly behind card.